For the deformation and evaluation of reservoir accumulative landslide, it is of great significance to study the strength characteristics of slip zone soils under rainfall and reservoir operation. In ...this paper, slip zone soils from Tongjiaping landslide in the Three Gorges Reservoir area is taken as the research case, and the self-developed seepage device matching with the ring-shear test is designed and manufactured. Then, the shear strength of slip zone soils under different seepage-shear conditions is studied to reveal the strength evolution law of riverside landslide. Eventually, the creep characteristics of slip zone soils are described by the Burger model. The experimental results indicate that: (1) the weakening effect of slip zone soils will be induced by the increase of seepage cycles, change amount of seepage pressure, initial and constant seepage pressure, which decrease the residual strength of slip zone soils. (2) When the seepage cycles are <15, the weakening of residual strength of slip zone soils is not obvious. While when the cycles reach 20, the residual strength of soil samples decreases rapidly. (3) The Burger model, which connected the Maxwell model and Kelvin model in series can appropriately reflect the creep characteristics of slip zone soils of Tongjiaping landslide. The research results reveal the weakening law of mechanical strength of slip zone soils under seepage cycles, which provides a basis for the mechanism of accumulative landslide under the fluctuation of reservoir level.
•The soil sample seepage device matching with the ring-shear test is designed and manufactured.•Shear strength of slip zone soils under different seepage-shear conditions is carried out.•Creep characteristics of slip zone soils are described by the Burger model.
An innovative approach based on a surface functional monomer-directing strategy for the construction of a sensitive and selective molecularly imprinted electrochemical sensor for patulin recognition ...is described. A patulin imprinted platinum nanoparticle (PtNP)-coated poly(thionine) film was grown on a preformed thionine tailed surface of PtNP-nitrogen-doped graphene (NGE) by electropolymerization, which provided high capacity and fast kinetics to uptake patulin molecules. Thionine acted not only as a functional monomer for molecularly imprinted polymer (MIP), but also as a signal indicator. Enhanced sensitivity was obtained by combining the excellent electric conductivity of PtNPs, NGE, and thionine with multisignal amplification. The designed sensor displayed excellent performance for patulin detection over the range of 0.002–2 ng mL–1 (R2 = 0.995) with a detection limit of 0.001 ng mL–1 for patulin. In addition, the resulting sensor showed good stability and high repeatability and selectivity. Furthermore, the feasibility of its applications has also been demonstrated in the analysis of real samples, providing novel tactics for the rational design of MIP-based electrochemical sensors to detect a growing number of deleterious substances.
The development of polymer-based composites with a high thermal conductivity and electromagnetic interference (EMI) shielding performance is crucial to the application of polymer-based composites in ...electronic equipment. Herein, a novel strategy combining ice-templated assembly and stress-induced orientation was proposed to prepare polydimethylsiloxane (PDMS)/alumina/carbon fiber (CF) composites. CF in the composites exhibited a highly oriented structure in the horizontal direction. Alumina was connected to the CF, promoting the formation of thermal conductive pathways in both the horizontal and vertical directions. As the CF content was 27.5 vol% and the alumina content was 14.0 vol%, the PDMS/alumina/CF composite had high thermal conductivities in the horizontal and vertical directions, which were 8.44 and 2.34 W/(m·K), respectively. The thermal conductivity in the horizontal direction was 40.2 times higher than that of PDMS and 5.0 times higher than that of the composite with a randomly distributed filler. The significant enhancement of the thermal conductivity was attributed to the oriented structure of the CF and the bridging effect of alumina. The PDMS/alumina/CF composite exhibited an excellent EMI shielding effectiveness of 40.8 dB which was 2.4 times higher than that of the composite with a randomly distributed filler. The PDMS/alumina/CF composite also exhibited a low reflectivity of the electromagnetic waves. This work could provide a guide for the research of polymer-based composites with a high thermal conductivity and an EMI shielding performance.
► Acid-insoluble residue increased to 38.2 from 30.1% in torrefied biomass at 330°C. ► 51% of lignin modified via demethoxylation in torrefied biomass at 330°C. ► Aromaticity increased from 35.8 to ...59.6% in torrefied biomass at 330°C. ► Non-protonated aromatic carbon fraction increased during torrefaction.
In this study, the effect of torrefaction on the chemical and structural transformation of lignocellulosic biomass was investigated using complementary analytical tools. It was observed that the acid-insoluble fraction was increased from approximately 30 to 38% and the methoxyl content was decreased to about half after torrefaction at 330°C for 2.5min. These results highlight the formation of condensed structures along with lignin transformation via demethoxylation. Solid-state NMR spectroscopy indicated that upon torrefaction the aromaticity increased from about 36 to 60%. For the sample torrefied at 330°C, the non-protonated aromatic carbon fraction was found to be about 60% of total aromatic carbons, indicating the formation of large aromatic clusters. The complementary analyses used in this study are proposed as a suitable approach for the elucidation of chemical and structural transformation of biomass during thermal treatment.
Sorbicillinoids are important hexaketide metabolites derived from fungi. They have a variety of biological activities including cytotoxic, antioxidant, antiviral and antimicrobial activity. The ...unique structural features of the sorbicillinoids make them attractive candidates for developing new pharmaceutical and agrochemical agents. About 90 sorbicillinoids have been reported in the past few decades. This mini-review aims to briefly summarize their occurrence, structures, and biological activities.
The inflammability of polystyrene (PS) limited its application. In order to improve the flame retardancy of PS, developing reactive-type flame retardants is a promising approach. In this work, a ...novel N-arylpiperazine phosphoramidate monomer, 2-((phenoxy(4-phenylpiperazin-1-yl)phosphoryl)oxy)ethyl methacrylate (PPPEM), was facilely synthesized and used as a reactive-type flame retardant. The obtained monomer was then copolymerized with styrene through the free radical bulk polymerization. The thermal stability of copolymers was measured by the thermogravimetric analysis. The addition of the PPPEM units increased decomposition temperature of the copolymers, indicating the improvement of the thermal stability. The glass transition temperature of the copolymers remained little changed with varied amount of the PPPEM, implying that the introduction of PPPEM units did not evidently affect the mobility of the PS main chain. The flammability of the copolymers was evaluated by microscale combustion calorimeter (MCC) and limiting oxygen index (LOI). According to the MCC and LOI results, PPPEM unites can contribute to the decrease of the peak heat release rate, the increase of LOI and improvement of the flame retardancy. The novel N-arylpiperazine phosphoramidate monomer show a great potential for application in reactive-type flame retardants.
•The degradation and combustion properties of bio-oils were quantitatively evaluated.•The formation and effect of carbonaceous solid during bio-oil combustion were studied.•A higher amount of ...carbonaceous solid was produced from aged bio-oil.•Bio-oil from torrefied wood has comparable thermal profiles with raw bio-oil.•Bio-oils have comparable combustion index with fuel oils used in boilers.
The degradation properties and combustion performance of raw bio-oil, aged bio-oil, and bio-oil from torrefied wood were investigated through thermogravimetric analysis. A three-stage process was observed for the degradation of bio-oils, including devolatilization of the aqueous fraction and light compounds, transition of the heavy faction to solid, and combustion of carbonaceous residues. Pyrolysis kinetics parameters were calculated via the reaction order model and 3D-diffusion model, and combustion indexes were used to qualitatively evaluate the thermal profiles of tested bio-oils for comparison with commercial oils such as fuel oils. It was found that aged bio-oil was more thermally instable and produced more combustion-detrimental carbonaceous solid. Raw bio-oil and bio-oil from torrefied wood had comparable combustion performance to fuel oils. It was considered that bio-oil has a potential to be mixed with or totally replace the fuel oils in boilers.
This study explores the impact of supply chain finance on industrial efficiency and the internal mechanism. The super-efficiency model and quantitative analysis method were used based on the time ...series data of the ICT industry in Shenzhen from 2005 to 2020. In order to better investigate the impact of supply chain finance on industrial efficiency, this study categorized industrial efficiency into operational efficiency and innovation efficiency to reflect the durability and virtuousness of the industry development. Results indicate that supply chain finance has an inverted U-shaped nonlinear effect on industrial efficiency. Even though the long-term effect on operational efficiency is positive, the effect on innovation efficiency reveals an inverted U-shape, mainly due to the mediating effect of industrial concentration. Theoretically, this study sheds light on the intricate effects of supply chain finance at the industrial level, and also provides valuable insights into the potential inhibition mechanism, which enriches and deepens the related research on the supply chain finance from the nonlinear perspective, make the research findings more consistent with the fact of industrial development and avoid the linear stereotypes of the existing theory consensus. Practically, it is conductive to an objective understanding for managers and policymakers, so that supply chain finance can facilitate both operational and innovation efficiencies and realize the effective integration of supply chain finance and industrial development.
Plain Language Summary
The purpose of this study aimed to explore the impact of supply chain finance on industrial efficiency. Authors conducted quantitative analysis based on the time series data of the ICT industry in Shenzhen from 2005 to 2020. In order to better investigate the impact of supply chain finance on industrial efficiency, this study categorized industrial efficiency into operational efficiency and innovation efficiency to reflect the durability and virtuousness of the industry development. Results indicate that supply chain finance can indeed greatly improve industrial efficiency. However, this improvement is more from the perspective of operational efficiency at the industrial operation level. In the long run, excessively developed supply chain finance will lead to excessive concentration on the supply side, and excessively powerful supply chain finance enterprises will also squeeze the survival space of small and medium-sized enterprises in the serviced industry, ultimately causing the entire industry to lose its innovative vitality due to the increased industrial concentration. Theoretically, this study sheds light on the intricate effects of supply chain finance at the industrial level, and also provides valuable insights into the potential inhibition mechanism, avoid the linear stereotypes of the existing theory consensus. Practically, it is conductive to an objective understanding for managers and policymakers to realize the effective integration of supply chain finance and industrial development. This study also encountered limitations from sample range and particularity, which make it faced the challenge of theoretical robustness when extending to traditional industries.
The extensive exposure to multiple mycotoxins has been demonstrated in many countries; however, realistic assessments of the risks related to cumulative exposure are limited. This biomonitoring study ...was conducted to investigate exposure to 23 mycotoxins/metabolites and their determinants in 227 adults (aged 20-88 years) in the Yangtze River Delta, China. Eight mycotoxins were detected in 110 urine samples, and multiple mycotoxins co-occurred in 51/227 (22.47%) of urine samples, with deoxynivalenol (DON), fumonisin B1 (FB1), and zearalenone (ZEN) being the most frequently occurring. For single mycotoxin risk assessment, FB1, ZEN, aflatoxin B1 (AFB1), and ochratoxin A (OTA) all showed potential adverse effects. However, for the 12 samples containing DON and ZEN, in which none had a hazard risk, the combination of both mycotoxins in two samples was considered to pose potential endocrine disrupting risks to humans by hazard index (HI) method. The combined margin of exposure (MOE
) for AFB1 and FB1 could constitute a potential health concern, and AFB1 was the main contributor. Our approach provides a blueprint for evaluating the cumulative risks related to different types of mycotoxins and opens a new horizon for the accurate interpretation of epidemiological health outcomes related to multi-mycotoxin exposure.
Ustilaginoidins are a kind of mycotoxins with 9,9'-linked bis-naphtho-γ-pyrones structures produced by the rice false smut pathogen Villosiclava virens. These metabolites displayed a wide range of ...bioactivities, such as teratogenic, cytotoxic, phytotoxic, and antibacterial activities. So far 26 ustilaginoidins have been isolated from V. virens, among which 18 compounds contained stereogenic center(s), however, most of them were unknown for the absolute configurations, except that of ustilaginoidin D. In this study, the absolute structures of these ustilaginoidins were constructed for the first time by analysis of the biosynthetic monomers obtained from a gene knockout mutant (ΔUV_2091) of V. virens. The gene UV_2091 was predicted to encode an enzyme that dimerized the monomeric naphtho-γ-pyrones in V. virens. Knockout of this gene led to the accumulation of three monomers, namely hemiustilaginoidin F (1), epihemiustilaginoidin D (2), and hemiustilaginoidin D (3), but the production of ustilaginoidins was completely blocked. The structures of the monomers were deduced by spectroscopic analysis, in combination with TDDFT ECD calculations for determining the absolute configurations. These compounds were tested for their phytotoxic, cytotoxic, antibacterial, and antifungal activities. Compounds 1 and 3 showed inhibition against the radicle and plumule elongation of rice and lettuce seeds at the tested concentrations. Compound 1 was active against the tested five human cancer cells, with half maximal inhibitory concentrations (IC
s) of 13.2~37.3 μM. Compounds 1~3 inhibited the growth of the tested pathogenic bacteria with minimum inhibitory concentrations of 8~32 µg/mL, while compound 3 exhibited antifungal activity against Magnaporthe oryzae (IC
, 5.21 µg/mL). A comparison of these data with those of the ustilaginoidins provided insights into the structure-bioactivity relationships.
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